Stoker.



D. P, CRAWFORD. STOKER. APPLICATION FILED APIE.; 1909. "i, 1 1 9,927., Pateted Dec. 8, 1914.

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WITNESSES mvEfNTQn #W7 MM MWI @j M D. F. CRAWFORD.

Patented Dec. 8, 1914.

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' INVENTOR M NITED i DAVID F. CRAWFORD, 0F PITTSBURGH, PENNSYLVANIA.

sToKnR Application iiled April 3,A 1909i v Serial o. 487,615.

-]balwh01liit fmay concern;

Be it known that 1 DAVIDE. Cnawronmaf citizen of the United States, resid ing at Pittsburgh,'in thecountyf of Allegheny and State of Pennsylvania., have invented certainv `new and useful Improvements in Stole'rs,o f

which the following is a specification'.

The inventionv relates to automatic 'stok 'ersof the underfeed typeand particularly to the trough and feed meclianisin.l The in-f vention has for its primipal4 objects; fthe provision of an vimproved. form'of *step-by step' feed adapted to give -a more-positive and effective vfeed than the devices" of this character Y heretofore employedA th'e'` provision 'of 'an improved formof feed trough.

constructed :to permit 'ag'supplyof air ltor-be. forced therethrough in order toliprinote combustion ofl the .fuel Iabove the; trough;

and the provision of improved meansl forl supplying 'fuel to thee-nd of-lthe .feed trough.

One embodiment lofthe invention is' .i l lus.' trated. in. the accompanying: drawings, wherein- :Figure "1 'is; a: partial'v horinontalnisection taken'abvethefgrates Figure 2 isa vertical troughs, and

Figure 1 `is a longitudinal horizontal sec-V tion taken through the-upper end of the con-l necting rods of'FigureB, and showingsuch rods' in plan View. v

The Stoker is illustrated as appliedto ai locomotive fire-box, but it-Will be understood that the ,construction vis of generalapplica# tion and not limited to use in the relation shown. Only so vmuch Aof the fire-box 'is shown as is necessary to illustratethe relation of the parts.

.Referring first to the genera-1 l arrangement of parts as shown inFigures v1 and 2,'the principal parts'xnay beenumeratedV as fol?. lows; 1 is the re-box,which may. be offany approved type 2 .andB are the feed troughs lextending longitudinally through-'the furnac'e/i and 5 are hoppersor receptacles from whichthefuel is fed Ioi* supplied to the rear ends of the feed troughs Zand- 3 ,6j and Aare the side grtes locatedlupon the outer sides ofitb troughs '2 and 3'; '8 -is the center grate located intermediate thetronghs Y Zand 3; 9 and 10 aledropgratie extending v` Specification of Letiers'Patent.

section., .through -thefcenter "of one'v of .thef'eedis' van l.enlarged l section taken vthrough the 'center ofV oneof thel feed across the vfront end of 'the furnace i1115 Patented Dec'. 8, 1914; I

operating shaft from 'which the meinh'ei'sff steam-.cylinder foroscillating thev shaft' 11 back and-forth and 'connected thereto-brv means of the crankvl upon the shaft 11,1.:1`

connectingrod 11 secured-tothe endofjtle crank, and Athe hollow piston- 1 5 in n'h'ich thcconnecting rod is pivoted.

The 'g'rates-fG, 'Z and S are sulistantiall)v similar vin'"f :on'struction and coinprise'n seriesof bars 16` mountedfor oscillation, andv provided 'with i oppositely projecting fingers 17. j. Each A"of ythese brace'barsfis provided at its end with' a'; downwardly. projecting a rin 18 2) end thejends 'of .these ,arms 'are' connected to longitudinally extending -barsf 19, and each Series'of bracesmay" be agitated b'yf'nieansof the'r'rsual connections extending tq the ,rear of: the furnace.

f f llwofeed troughs 2"-and. 3- a1re lnovided, which troughs are t e .saine inf construction' s ojtlnt a'ldescription of lone will suffice for both., ils' indicated vin Figure.. 3,' the troughis provided upon its,-bt'ittjomwith la serres oftrans'versetrunicated' ridges F20. 21 .and9. '2, and the membeisZ, 24,25' and^-26 fare pro vided for'feeding 'the 'fuel upirard .andA for- The member 125 is operated directly from the crank arrn28 by means ofthe connecting rod 29, and the membersfand 23am operated in unison ,with-the member 2 5 by means ofthe pairs of connecting 'links 30 and 31. The member- 21 is operated ironia p air of cranks 3Q (Fig. hyvmeans' ofthe connecting rod 33, whose forked end ein braces Athe cranks 32. The member. 2" is also operated from the pair of cranks 3Q bj.' means of the connecting rod 31 whose lower -end is pivoted between the' .ends of the cranks 32. `The provision of .the transverse .ridges .20, 21 Sand Q2 reduces the tendency the feed mechanism are operated in ainzh` A ncr to be hereinafter described; and 12 is :x7-6 0 of the coal at the surface of the trough to cake as the ridges promote an upward feed of the fuel. through the trough. The arrangement 'involving the ridges with the oppoinclined walls with the feed members the ridges is advantageous, as thc ci l passing over the crest of a ridge is directed down the inclined rear face of the ridge and on to'a feed member there being no dead space for the collection of fuel whenthe feed members are in thel position of the members 25 and Q6 in Fig. f2.. It will be noted' that the feed members 2T, 23.7 24 and 25 act in alternation, which arrangement is also advantageous in that a feed member in advance of another feed member positioned to receive the coal fed forward by the preceding member, and the operation is much more effective and positive than is the case where the feed members are all similarly positioned and act in unison. The two forward feed members 25 and 26 are arranged to act in vunison as the rapid forward feed of the fueLis not as necessary at this point as at a. point -farther back in the trough. The combined arrangement of transverse ridges and feed members serves to keep the mass of fuel in the troughwell loosened up, and feeds'it upwardly and forwardly in such an effective and uniform manner that little or nohand-ringis necessary. The truncating of the ridges 20, 21 and 22 provides air spaces 36 through which air ffom the ash pit is forced, thus serving still further to agitate the mass of material in the trough, and promote the coking and combustion of the coal at the surface of the trough. 'I he provision of the feed member 27 in the hopper 4 insures a proper delivery of fuel to the end of the trough, and relieves the fireman of the necessity of forcing the fuel forwardly, the only manual attention necessary being the maintenance of a proper amount of fuel in the hopper. The downward inclination of the floor of the hopper also assists in securing a proper forward feed.

Having thus described my invention and illustrated its use, what I claim as new and desire to secure by Letters Patentl is the-following z- 1. In an underfeed Stoker, a feed trough' provided with a series lof transverse ridges each comprising a pair of. oppositely inclined walls, a series of movable feed members between the ridges for feeding the fuel a upwardly and forwardly'from the depressions between the ridges, and means for operating the said members.

2. In an underfeed Stoker, a feed trough provided with a series of transverse truncated ridges having air passages through their cut off portions and each comprising a pair of oppositely inclined walls, and means between the ridges for feeding fuel through the trough. l g

3. In an underfeed Stoker, a feed trough provided with a series of transverse ridges,

each comprising a. pair of oppositely in-' v- RAWFORD. 

